erector spinae iliocostalis (lateral column), longissimus (intermediate column), spinalis (medial column)
The intermediate layer of intrinsic back muscles, also known as the erector spinae (chief extensors of the vertebral column) comprise of:
erector spinae iliocostalis
extends and laterally bends vertebral column and head
dorsal rami
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main actions:
innervation:
blood supply:
Longissimus
extends and laterally bends vertebral column and head
dorsal rami
Identify the muscle
main actions:
innervation:
blood supply:
spinalis
extends and laterally bends vertebral column and head
dorsal rami
Identify the muscle
main actions:
innervation:
blood supply:
trapezius, latissimus dorsi, levator scapulae, rhomboids
What are the superficial extrinsic back muscles?
trapezius
elevates, retracts, and rotates scapula
accessory nerve (CN XI)
transverse cervical artery, dorsal perforating branches of posterior intercostal arteries
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Main actions:
Innervation:
Blood supply:
levator scapulae
elevates scapula medially, inferiorly rotates glenoid cavity
dorsal scapular nerve
dorsal scapular artery, transverse cervical artery, ascending cervical artery
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Main actions:
Innervation:
Blood supply:
latissimus dorsi
extends, adducts, and medially rotates humerus
thoracodorsal artery
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Main actions:
Innervation:
Blood supply:
rhomboid major and minor
fixes scapula to thoracic wall, retracts and rotates it to depress glenoid cavity
dorsal scapular nerve
dorsal scapular artery
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Main actions:
Innervation:
Blood supply:
serratus posterior superior, serratus posterior inferior
The intermediate layer of extrinsic back muscles comprise of:
Serratus Posterior Superior
(proprioception) elevates ribs
ventral rami of upper thoracic nerves (first four intercostals)
posterior intercostal arteries
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Main actions:
Innervation:
Blood supply:
serratus posterior inferior
(proprioception) depresses ribs
ventral rami of lower thoracic nerves (last four intercostals)
posterior intercostal arteries
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Main actions:
Innervation:
Blood supply:
splenius capitis and splenius cervicis
What are the superficial intrinsic back muscles?
bilaterally: extend head
unilaterally: lateral flexion and rotates neck to same side
dorsal rami of middle cervical nerves
descending branch of occipital artery, deep cervical artery
Describe action, innervation, and blood supply of splenius capitis
bilaterally: extend head
unilaterally: lateral flexion and rotates neck to same side
dorsal rami of lower cervical nerves
descending branch of occipital artery, deep cervical artery
Describe action, innervation, and blood supply of splenius cervicis
keeps head upright and maintains posture
What is the significance of this muscle?
proprioception as opposed to motor
The intermediate extrinsic back muscles (serratus posterior) are thin muscles whose main function is intended for:
serratus posterior muscles, particularly serratus psoterior superior
Which muscles have been implicated as a source of chronic pain in myofascial pain syndromes?
semispinalis, multifidus, rotatores
Identify and describe the intrinsic deep back muscles (AKA Transversospinalis Muscle Group)
Multifudus
Stabilize spine
dorsal rami of spinal nerves
cervical: deep cervical artery
thoracic: dorsal branches of posterior intercostal arteries
sacral: dorsal branches of lateral sacral arteries
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List action
Innervation
blood supply
rotatores (transverse to spinous process)
stabilize, extends, rotates spine
dorsal rami of spinal nerves
dorsal branches of segmental arteries
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List action
Innervation
blood supply
Interspinalis (spinous process to spinous process)
aid in extension of vertebral column
dorsal rami of spinal nerves
cervical: deep cervical artery
thoracic: dorsal branches of posterior intercostal arteries
lumbar: dorsal branches of lumbar arteries
Identify the muscle
List action
Innervation
blood supply